One of the planets in the TRAPPIST-1 system, just 40 light-years from Earth, may have an atmosphere capable of supporting life, Science Alert reported. Recent observations with the JWST space telescope indicate signs of a gaseous envelope around the Earth-like TRAPPIST-1e, which could allow for liquid water on its surface.

The discovery is preliminary and requires further study, but it is the closest astronomers have come in the search for a “second Earth.” “TRAPPIST-1e remains one of the most attractive planets in the habitable zone, and these new results bring us closer to understanding what type of world it represents,” said astronomer Sara Seager from the Massachusetts Institute of Technology (MIT), co-author of one of the two studies.

Astronomers use Earth as a template when searching for habitable worlds beyond the Solar System, with a key criterion being the possibility of liquid water — essential for biochemical processes. The planet must be at a suitable distance from its star, where water does not freeze or evaporate.

TRAPPIST-1 is a red dwarf with seven rocky exoplanets, several of which lie in the star’s habitable zone. However, the activity of red dwarfs — strong solar flares — may have stripped the atmospheres from planets in the system. TRAPPIST-1d shows no signs of an atmosphere, but TRAPPIST-1e is more favorably positioned at a greater distance from the star.

The team led by astronomer Néstor Espinoza from the Space Telescope Science Institute and Natalie Allen from Johns Hopkins University observed the starlight as TRAPPIST-1e passed in front of the star to detect changes indicating the presence and composition of an atmosphere. A second team, led by astrophysicist Ana Glidden from MIT, interpreted the results.

The analysis suggests two possibilities: the planet is either a “bare rock” or has a so-called secondary atmosphere rich in molecular nitrogen, with small amounts of carbon dioxide and methane. If confirmed, TRAPPIST-1e could be the most Earth-like exoplanet discovered to date.

“We are still in the early stages of scientific discovery with Webb. It is astonishing to measure the details of light around Earth-sized planets, 40 light-years away, and to understand what might be there and whether life is possible,” Glidden said.

Scientists expect new JWST observations that will confirm or refute the presence of the atmosphere, a key step toward understanding the habitability of TRAPPIST-1e. | BGNES